[13.09] Uncertainties in Spiral Galaxy Projection Parameters

E.I. Barnes, J.A. Sellwood (Rutgers University)

We have investigated the impact of nonaxisymmetric structure
on estimates of galaxy inclinations and position angles. Our
investigation has revealed several points. First, systematic
uncertainties associated with fitting photometric data
dominate the formal statistical uncertainties. Second, the
differences between projection angles determined with
photometric data versus kinematic data are, on average, the
same magnitude as the systematic uncertainties. Third, small
differences between photometric and rotation centers do not
significantly alter derived inclinations or position angles.
Finally, we find no direct evidence for intrinsically
elliptical galaxy disks.